The present invention relates to a method for cooling hot particulate material which has been subjected to heat treatment in an industrial furnace, such as a rotary kiln for manufacturing cement clinker, by which method the hot material from the kiln is directed to an inlet grate in a cooler, in which cooling air from an underlying compartment is led via a number of channels through gaps in the inlet grate for cooling the hot material and where compressed air from a separate system via a number of ducts can be intermittently injected into the material on the inlet grate. The invention also relates to a cooler for carrying out the method.
A cooler of the aforementioned kind is known from EP 0 780 651 in which compressed air at a pressure of more than 345 kPa is intermittently injected in a substantially horizontal manner into the material on the grate so as to dislodge any agglomerates and so-called snowmen formations formed by the agglutination of clinker material, and resulting in reduced performance efficiency of the cooler. The disadvantage of this known cooler is that large snowmen formations and agglomerations which may weigh up to several tons cannot be completely removed or pushed along in the cooler by means of injections in the horizontal direction of movement of the material. For this known cooler it may be possible to reduce the extent of snowmen formations, but it will not be possible to achieve complete elimination of such formations. For this known cooler there is also a risk of clinker dust by the compressed air being blown through the grates and down into the underlying system of ducts.